Pads for electrodes have conventionally been used for apparatuses such as electrocardiograph apparatuses, electroencephalograph apparatuses, and electromyograph apparatuses, which extract and measure electrical signals from subjects to be measured.
For example, PTL 1 discloses a biomedical pad for electrodes provided with a hydrous gel layer and using the hydrous gel layer in close contact with a living body surface. In addition, PTL 2 discloses a polymer hydrogel electrode provided with a conductive polymer hydrogel and an electrode element, which is used with the conductive polymer hydrogel being attached to a human body and a surface of an object.